Root canal instruments for manual use: a review

Root canal instruments can be subdivided into instruments made of different alloys (stainless steel, nickel-titanium and nickel-aluminium) and instruments with different geometric forms (e.g., instruments with short cutting segments). Several types of stainless steel and titanium-based instruments are presented and assessed by a review of the current literature. In summary, flexible stainless steel instruments with noncutting tips seem to be a decisive improvement in the development of an ideal root canal instrument. They are superior to titanium-based instruments in both cutting efficiency and instrumentation of curved root canals.